Process plants such as chemical and petrochemical plants comprise hundreds of thousands of interrelated components ranging from individual devices, such as control valves, to complex plant equipment such as multi-stage compressors and heat exchangers, for example. Each of these components must operate continuously in a safe, efficient and effective mode in order for the entire plant to operate within predetermined levels of safety, quality and production.
Accordingly, hundreds of such devices, loops and equipment are required to effectively control the plant, and in turn, these assets must be constantly monitored for their optimal operations.
Countless prior art performance monitoring systems have been devised as attempted solutions, but all have had serious shortcomings and/or created problems themselves. For example, those based only on Key Performance Indicators (KPIs) do not produce an integrated presentation of the necessary information since they concentrate only on the process control loop level. Similarly, other systems focus on higher, supervising levels, but only by measuring against past performance and projected targets. These systems are not seamlessly integrated into the operation and maintenance layers, as does the present invention whereby an integrated and comprehensive view is provided of the total plant performance at the device level, control loop level and equipment level.
Moreover, while there have been prior loop and device performance monitoring systems, such prior systems have required highly skilled operators to interpret the results, and the results do not directly tie to the KPIs currently in use as does the system of the present invention. Other prior attempts have suffered from converting data overload problems for the operators into information overload problems, whereas the system of the present invention normalizes the complex results into only 3 states such as, for example, “Excellent”, “Good/Deteriorating” and “Bad”. Further, these can be colour coded so that highly skilled operators are not required, and errors of interpretation are avoided.
By way of example, a typical scenario is illustrated in FIG. 1 wherein a production run is started at 40 and the production 42 continues, while quality checks 44 are performed, until the product is detected to be offspec as indicated at 46. The operator then begins a trouble shooting program 48 in an effort to determine the cause of the problem. As illustrated by way of example, the problem may involve the PID (Proportional-Integrated-Derivative) tuning 50, or the APC (Advanced Process Control) 52 may have become inactive, or a breakdown 52 may have occurred. Only after this determination is made can the problem be corrected, which may involve unacceptable downtime and/or loss of product before production may be resumed.
Contrary to this conventional approach, the performance monitoring control system of the present invention compares all of the sensed conditions, at three different levels as will be more fully explained hereinafter, and produces an integrated, overall and deterministic presentation to the operators. In addition, the complete presentation may be broken down into information segments of particular concern to different classes of plant personnel such as, for example, maintenance, operations, and management.
Other problems of prior art systems include such disadvantages as being limited to the diagnostics of the component supplier, or discounting the current health of the existing equipment and relying only on periodic maintenance, or an over reliance on RBI (Risk-Based Inspection) and RCM (Reliability Centered Maintenance) analysis rather than immediate identification a problem or potential problem before it occurs. These and other problems of prior art systems are solved by the present invention, along with providing other substantial advantages as will become clear from the following description of one preferred embodiment of the present invention.